The recent Asean Summit in Phnom Penh drew considerable international attention even amid the missiles in Gaza and another crisis in Europe. This attention had little to do, intrinsically, with the group of 10 countries.

The summit's significance is magnified through the lens of US-China competition: US President Barack Obama took his first overseas trip since winning re-election; this was perhaps the last visit by outgoing Premier Wen Jiabao . Over the past two years, the Obama administration has made a concerted "pivot" to the region, whereas Beijing has seen alarm raised with its neighbours over territorial disputes.

Obama did well. Recall his first visit in 2009, when he was assailed in the American press for being too soft. This time, he pushed and persuaded on both economics and politics.

In Bangkok, the US reminded Thais of their long-standing alliance and prodded them towards entering the US-led Trans-Pacific Partnership for closer economic links. In Yangon, Obama - the first American president to visit the country - met reformist President Thein Sein, and uttered the word "Myanmar". He then embraced - quite literally and heartily - iconic opposition figure Aung San Suu Kyi and called the country "Burma". The human rights question about problems in Rakhine state was raised but had to be expected, given criticism that the presidential visit was premature.

Add this to strengthened ties with Indonesia, Singapore, Vietnam and the Philippines, and the Obama administration's first term will be noted for re-engaging the Association of Southeast Asian Nations. Credit goes to US Secretary of State Hillary Rodham Clinton, who has been proactive in paving the way for the president.

But another factor has been China. Concerns about Beijing's ambitions have made other Asians much more receptive to American attention.

It doesn't help that Beijing stands accused of influencing Cambodia as the Asean chair; the group's ministerial meeting in July floundered. The latest summit also showed signs of disunity when Cambodia's draft statement led several leaders to reiterate their positions and insist on rewording the text to salvage the situation.

Amid this, Obama did not need to stoke anxieties about China. He instead had the luxury of urging all sides to show restraint. When Asians can't get along with each other, the position of the US is reinforced.

Intra-Asian differences will continue. The Philippines - most vocal about Chinese maritime claims - has called for a meeting with other Asean claimants Vietnam, Malaysia and Brunei. China is pointedly excluded.

How Chinese leaders now respond can potentially shape relations with the region as a whole. So far, China has punished the Philippines by cutting off tourist visits, buying overpriced rice from Thailand's Yingluck Shinawatra government, asserting influence over Cambodia and provoking an Asean schism. These cannot be Beijing's mainstays.

China has always said it supports Asean centrality and its response needs instead to be broader and forward-looking.

After all, China's economy continues to grow while the US stands at the edge of a fiscal cliff. So while Asians welcomed Obama, questions linger over the American wherewithal to remain engaged and grow alongside Asia. China should put trade and investment at the front and centre of its engagement with the rest of Asia - and not territorial disputes.

Accordingly, China would do well to give attention to something else that was launched at the summit: the Regional Comprehensive Economic Partnership, to link Asia from China to India, with Asean as the hub, and others like Australia also in the frame.

Despite all of Obama's charisma, the US is not within this economic group and instead champions the Trans-Pacific Partnership.

The Regional Comprehensive Economic Partnership sets the stage for a new era of Asian regionalism, centred on economics.

If it can make the agreed deadline of 2015, this wider effort would support Asean's own target for community integration. Discussions are still at a preliminary stage and there are many obstacles ahead.

But if it can progress, the partnership will provide many avenues to broaden the agenda and create more positive perceptions about China's role in Asia. Beijing should do all it can to help Asean move forward with this.

Simon Tay is chairman of the Singapore Institute of International Affairs and teaches international law at the National University of Singapore Faculty of Law

This article appeared in the South China Morning Post print edition as Economy first